Image display systems create images by emitting or modulating light. The light forms an array of picture elements, or pixels, which together form a viewable image. While most light modulators can create multiple intensity levels, true digital light modulators, such as the Digital Micromirror Device (DMD) cannot. Without the capability to create multiple brightness levels, digital light modulators rely on a binary pulse width modulation scheme to create various intensity levels by turning a modulator element on and off very rapidly. This modulation scheme, however, can create inefficiencies which lower the intensity of the displayed image.
Intensity, or image brightness, is only one of many metrics, including horizontal and vertical resolution, color purity, display size, frame rate, and immunity from device created image artifacts, by which display systems are judged. Some of these characteristics are more important to consumers, either because they create a noticeably superior image, or simply because they differentiate between the display systems on display in a store. Brightness is one metric that is extremely important to purchasers of display systems. Therefore, an improved modulation scheme and system are needed to increase the image brightness available in pulse width modulated display systems.